LOS ANGELES (AP) -- A nurse who treated Michael Jackson has testified the singer asked her to help him get the powerful anesthetic propofol.

Nurse practioner Cherilyn Lee told jurors Tuesday that Jackson complained he could not sleep and asked her for the drug two months before he died.

Lee says she initially didn't know about the drug, but after speaking with a doctor told the singer it was unsafe to use in his home.

Lee was called to testify by defense attorneys for Dr. Conrad Murray, who has pleaded not guilty to involuntary manslaughter. Authorities say he provided the singer with the fatal dose of the drug.

Lee says Jackson told her he had received propofol during surgery but didn't mention any doctors who were involved.

She says Jackson told her propofol was the only drug that would help him sleep.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

The judge hearing the involuntary manslaughter trial of Michael Jackson's doctor blocked defense lawyers from asking about the singer's multimillion-dollar contract for his final concert series.

Defense attorneys for Dr. Conrad Murray had wanted to introduce Jackson's contract with concert giant AEG Live to show that he would be heavily indebted to the promoter if the concerts were canceled. They said Jackson would be desperate to make sure the shows continued.

"This is not a contractual dispute. This is a homicide case," Pastor said.

Defense attorney Ed Chernoff told Pastor that Jackson would have been indebted to AEG Live for nearly $40 million if the shows were canceled. Chernoff contends that led Jackson to give himself a dose of the anesthetic propofol in a desperate attempt to sleep.

Prosecutors contend Murray, who has pleaded not guilty, gave the fatal dose.

Although Pastor blocked the AEG contract testimony, he will allow some testimony from Randy Phillips, the company's president and CEO. The judge said Chernoff could ask Phillips about putting together the shows, titled "This Is It," the singer's conduct during a March 2009 press conference and any issues that may have occurred with Jackson's performance of rehearsals.

Phillips is expected to testify later Tuesday, after jurors hear from Cherilyn Lee, a nurse practitioner who has said Jackson repeatedly asked her for propofol to help him sleep, but she refused.

Lee began her testimony Monday, the sixth witness that Murray's attorneys called to try to shift the blame for Jackson's death to the singer himself. Lee's testimony was briefly delayed Tuesday after she appeared flustered on the witness stand and said she had become dizzy.

Murray's team plans Tuesday to call other witnesses who they think may support that theory, including Phillips and Jackson's makeup artist and hairstylist, Karen Faye. They will also call several expert witnesses who will try to rebut the testimony of prosecution experts who said Murray was reckless and at fault in Jackson's unexpected death on June 25, 2009.

In a court filing Monday, Murray's attorneys expect Faye will testify that Jackson was distraught about completing the comeback shows.

One of the initial defense witnesses, Dr. Allan Metzger, supported prosecutors' contentions that Murray acted recklessly by giving Jackson propofol as a sleep aid and that the singer was looking forward to the show.

"He was excited," Metzger said of Jackson's demeanor during conversations and a house call in the months before the singer's death. "He was talking to me about some creative things that he was thinking about. He spoke to me about his excitement and his fear about the tour."

Metzger said Jackson felt the shows were a big obligation and he wanted to deliver stellar performances.

The doctor, who knew and treated Jackson for more than 15 years, testified the pop superstar asked him about IV medications during his house call.

On cross-examination, Metzger said he told Jackson that using any IV drugs or anesthetics to sleep was unsafe.

"You explained to him that it that was dangerous, life-threatening and should not be done outside of a hospital, correct," prosecutor David Walgren asked the doctor.

"That's correct," he replied.

"Was there any amount of money that would have convinced you to give him intravenous propofol in his house?" Walgren asked.

"Absolutely not," Metger said.

Lee was similarly against Jackson taking propofol to help him sleep. She told The Associated Press in 2009 that the singer repeatedly asked for the drug while she was treating him for nutrition and sleep issues.

"I said, `Michael, the only problem with you taking this medication' - and I had a chill in my body and tears in my eyes three months ago - `the only problem is you're going to take it and you're not going to wake up,'" she recalled telling Jackson.

Lee kept detailed notes of her treatments on Jackson, which she flipped through repeatedly while testifying Monday.

According to prosecutors, Murray kept no notes on his treatments on Jackson after signing on as his personal physician for the London shows.

Defense attorneys expect to conclude their case Thursday. Even if they do, jurors won't begin deliberations until next week. A judge told attorneys that he would give them the weekend to craft their closing arguments and finalize jury instructions.